


They fit together

by iloveyou10000



Series: I'm not half as good at anything as when I'm doing it next to you [1]
Category: Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Alpha Mary, Alpha Steve Rogers, Alpha/Beta/Omega Dynamics, Alternate Universe - Happy, Bucky Barnes & Steve Rogers Friendship, Domestic Avengers, Domestic Fluff, Family Dynamics, Family Feels, Family Fluff, Kissing, M/M, Making Out, Omega Peter, Omega Tony Stark, Omega Verse, Parent Steve Rogers, Parent Tony Stark, Peter Parker is Steve Rogers' Biological Child, Peter Parker is Tony Stark's Biological Child, Protective Steve Rogers, Protective Tony Stark, Romantic Fluff, Steve Rogers Feels, Steve Rogers Needs a Hug, Superfamily, Superhusbands, Sweet, Sweet Peter Parker, Tony Stark Has A Heart, Tooth-Rotting Fluff
Language: English
Status: Completed
Published: 2019-03-09
Updated: 2019-03-09
Packaged: 2019-11-14 10:24:01
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,651
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18050708
Author URL: https://archiveofourown.org/users/iloveyou10000/pseuds/iloveyou10000
Summary: “Did you finish your homework?” Questioned Steve.Peter gulped, and searched help in the other Omega’s eyes, who got the inquisitive look from the Alpha.“Uh-uh,” Peter said, warily, and Tony urged adding: “We got a bit distracted with, with, uh, well Petey came out with this brilliant idea and I swear Steve, it needs only some few improvements-”“Omega,” Steve cut him off, making him shiver, and settle.





	They fit together

The music stopped without warning, and two pairs of huge, chocolate brown eyes looked up to meet the most tender and stunning blue gaze they had ever seen in their entire life. Well, one of them was only 9 years old, but he was sure his Pops’ eyes were the bluest, the kindest, and the loveablest- the most loveable that ever existed.  
  
“Someone wanted to say hi, before going to bed,” Steve almost whispered in a low tone, with a soft smile. He was holding another kid, who was sitting on his arm and resting his head against his shoulder, eyes were already closed. They could hear nothing but at little rumble coming from her.  
  
“Hello, my favorite, beautiful Alpha,” Tony sang, lightly pushing on Peter’s back to make him get off his laps, where he was curled.  
  
Peter giggled and run toward the Alpha, instantly forgetting the project he was working on with Tony. The children could stay in the workshop only supervised by their parents, and only for a few hours- One member of the family addicted to that place was enough. And besides, Tony worked slower if he had to keep attention to them, even with JARVIS’ and the bots’ help. He didn’t really trust the bots to watch the kids; they were babies as well, so he often spent whole the time playing instead of working.  
  
Tony promptly followed his son, with a smirk on his lips that made Steve raise a quizzical brow. The Alpha lifted Peter up with his free arm, while Tony stepped in his husband’s space and pressed their mouth together, making Steve feel more his smile.  
  
“… and Steve,” he added, sinking his face in their daughter’s gold hair, but keeping eye contact with his mate. He watched as Steve’s lips parted in surprise and disbelief, and Tony chuckled before circling his neck with both arms.  
  
“Why does Mary get all the compliments?” A low, trembling growl resonated from Steve’s chest as a warning, but it wasn’t threatening. Steve’s rumblings were playful, peaceful, aroused or of warning, when he thought his Omega was exaggerating, but never hostile, not addressed to his family. Peter giggled too and purred a little.  
  
“Because she’s the prettiest,” the little one chirped, hiding his little lovely face in Steve’s neck. Both parents looked delighted by that statement, then Tony made a told-you-so face and kissed away Steve’s following pouting, that time with more emphasis, but always innocently.  
  
He purred louder than Peter, and Mary curled more in Steve’s embrace, agitated. She was already asleep, unable to resist the rocking movement of Steve coming down the stairs: he always chose the stairways on that purpose.  
  
“Can’t argue with that,” whispered the Alpha, while Tony pet delicately his daughter’s hair, murmuring shh and sweet words.  
  
“Goodnight sweetpea,” Tony purred, pressing a last kiss on a little hand clung to Steve’s white t-shirt.  
  
“Do I have to sleep too?” Asked Peter carefully, eyeing Tony first, then Steve. The older Omega huffed a laugh and looked at his high-tech watch to see what time it was. Peter had still half an hour before his bedtime.  
  
“Did you finish your homework?” Questioned Steve.  
  
Peter gulped, and searched help in the other Omega’s eyes, who got the inquisitive look from the Alpha.  
  
“Uh-uh,” Peter said, warily, and Tony urged adding: “We got a bit distracted with, with, uh, well Petey came out with this brilliant idea and I swear Steve, it needs only some few improvements-”  
  
“ _Omega_ ,” Steve cut him off, making him shiver, and settle.  
  
“I-It isn’t- It isn’t d-daddy fault,” the bottom lip of Peter trembled alarmingly, and Steve sighed, pressing a kiss on his forehead and hopping him a little, since he was sitting on his arm. In another situation, Tony would’ve melted: his Alpha’s chest was large, he had brooded shoulders and his super strength, _god, his power_ , allowed him to hold easily both their 9- and 4-year-old kids and still have agility to move almost effortlessly. Tony could’ve jumped on his back to be also carried, and the Alpha would’ve brought all of them upstairs.  
  
“Oh baby, it isn’t yours either. But you know the rules: you can’t re-frame the future with daddy, if you haven’t finished your homework yet,” Steve recalled quietly, still giving Tony the disappointing eye. “Why don’t you go finish them now, while we get your sister to bed? If you don’t need our help”  
  
“Uh-uh, piece of cake. I’ll do them suuuuper quickly,” the little Omega climbed out Steve, all scrambled and way too enthusiastic, and the Alpha let him go with a soft chuckle.  
  
“Keep an eye on him, J.” murmured Tony, watching his kid run away. He sighed happily and rest a shoulder against Steve’s chest and a cheek under his chin. The Alpha supported his weight, steady as a rock.  
  
“Always, Sir. I will make sure Peter will conclude his homework,” and the A.I. calling the kid by his name always brought back memories to Tony’s mind, that made his throat dry and his heart skip a beat. Jarvis, _the real one_ , called him by his first name, when Howard wasn’t nearby.  
  
Then Steve moved and Tony followed him to Mary and Peter’s bedroom. They walked in silence, and it was perfectly comfortable, but the Omega noticed something’s off: Steve had one free arm, and he wasn’t holding Tony by his hand or by his waist, even if he was on the side of that arm. It’s probably nothing, but they’ve never missed a chance to have their hands on each other for more than a decade, and Tony had an eye for details, especially the ones regarding his gorgeous Alpha.  
  
“Alpha?” He called in a whisper. Steve turned his head and Tony knew he did just by instinct because his eyes weren’t focused completely on him. He was thinking to something else. “Everything’s fine?”  
  
The Alpha smiled tenderly, and he leaned to kiss the top of his head, finally pressing a warm and protective hand on his back between his shoulder blades. “Of course, pretty Omega” he reassured, rumbling quiet.  
  
Tony shifted even closer, enjoying the long line of the Alpha against his side, his heat, and the way he could feel the deep voice vibrating through his chest. He felt the need to tilt his head back and purr all over it, but that would’ve been _counter-productive_ , so he settled for bumping his nose against Steve’s shoulder and inhaling the Alpha’s heavy scent with a quiet sigh.  
  
He believed Steve until he saw the expression while he tugged Mary’s covers and caressed her face. The Omega grabbed him by the shoulder, and searched his gaze looking at him intensely, then furrowed a little his brow. Steve answered to his silent question by shaking his head once, but then he seemed to reconsider, because he took Tony’s hand and guided him to the living room next to the kitchen, with the children within earshot.  
  
“What’s going on?” The Omega asked, while their bodies moved together, as if they were only one: Steve sat on the sofa and carried Tony down with him, who pressed his knees on both the Alpha’s sides. Tony circled his neck with both arms, and relaxed against his chest, while Steve wrapped him and brought him closer. Every movement was fluid, a dance they repeated many times through the years of their relationship.  
  
“It’s stupid,” Steve whispered after a few seconds. He kissed Tony’s neck, and hid his face, so the words came out muffled, but the Omega understood anyway. The difficult part was to stay focus on Steve’s problems, because the Alpha rubbed his nose where he marked him a long time ago, sucked his skin and scented him, and Tony just wanted to purr shamelessly, inviting his Alpha to do more, to bit him and to claim him, leaving him trembling and speechless-  
  
The Omega gasped and struggled for breath, stolen by Steve who licked right over the sensible bonding mark, grabbing possessively his hips and pressing his fingertips right there. Two of the sensations Tony loved the most: feeling the Alpha worship the particular spot on his neck, while leaving light bruises below the waist.  
  
Then, he felt Steve’s smirk opening on his neck, and he smacked him on a shoulder, telling him to be good. “Behave, Alpha,” Tony smirked too, and cup Steve’s face with both hands to meet his eyes again. The Alpha hummed and rumbled teasingly, and Tony quiet him by kissing his lips with playful pecks, light as butterflies.  
  
“Shouldn’t I tell you so, Omega?” His blue eyes sparkled with such a piercing ecstasy Tony felt his heart pumping faster, and shivers of arousal made him twitch between his legs. Steve read the excitement on his body, and responded with a long, deep growl from his throat.  
  
Tony bit his bottom lip, forcing his gaze to stay into Steve’s and not going down on his tasty lips. “Tell me what’s bothering you first,” he requested, and the demand sounded more like a plea. He knew Steve was trying to distract him, but he cared too much to let also the minor doubt bothering him.  
  
“It’s about the children’s homework,” Steve blurted out, even if it seemed hard for him. Tony watched him curious and slid a hand through Steve’s gold locks to massage him with his fingertips. He perfectly knew the points where to caress and where to press for his Alpha to relax, and his clever fingers found them immediately. Steve rumbled grateful, really sweet until Tony smiled.  
  
“Peter said they’re easy, and I know they aren’t, he’s already following most of the subjects they do in _12thgrade_. Mary is proving to be as smart as him, and one day they’ll be as brilliant as you… It made me recall the other day, when she asked me about the millennium problems, and in less than an hour she already knew more than me”  
  
“Do you really feel left behind?”  
  
“I… Yeah, I feel like that. Don’t look at me so incredulous, in a few years I won’t be able to help them with their scholarship program even if I want to, and they’ll realize they can’t count on me, because I’m just not-”  
  
“Not smart enough?” Tony interjected again, and Steve nodded uncertain. They pressed their front together, one breathing the air of the other.  
  
“Silly Alpha. Only a fool would believe our children won’t need you. They’ve so much to learn from you, one lifetime will not be half enough. Uh, uh, uh, don’t interrupt me. You’re intelligent Steve, you’re sharp, astute, and wise. Your stubbornness doesn’t make you give up on anything. You don’t avoid responsibilities and- And the most important thing, your best feature is- You make them feel loved. _Us_. Your heart it’s what made you the strongest man, and the best dad any kid could ever desire,” the last words came out a little broken, Tony’s voice wrecked and trembled, and he patted few times on Steve’s chest with a fingertip.  
  
The alpha sighed dreamily, remaining silent, watching Tony with the most intense and fondly look. Tony’s hand in his hair stopped, but just to wrap his head with both arms, hugging it tightly against his sternum.  
  
“They’ll always need you. I can manage their math’s problems and their scientific or humanities’ questions, but you are the righteous one, you know which limits we shouldn’t overcome. Sure, sometimes I don’t like when you keep me in line- _Ouch!_ Did you just…? Okay, okay, I hate it _every time_ \- hold that thought, by the way. The point here is: they’ll need it too, sooner than you think if they have inherited my chaotic nature, my impatience, my, uh, my impulsivity,”  
  
“Your creativity, your empathy, your strong sense of justice…”  
  
“Stop interrupting me,” the Omega’s growl was intimidating enough: he was trying to make a speech, a serious one. And for once, he wasn’t fishing for compliments. The Alpha just settled with a docile rumble which satisfied Tony enough to continue.  
  
“What I’m trying to say is,” he couldn’t restrain himself from laughing genuinely, and Steve pushed back his head to look at him with his brand confused-puppy look.  
  
“I’m fucking lucky,” the Omega admitted, another authentic laugh escaped his lips. He wasn’t crazy, he was so happy he couldn’t even stop himself from showing it, and the most charming smile lighted his face up. He cupped Steve’s cheek with one hand, the other hand’s fingers spread on his chest, right above his heart.  
  
“I love you, and we’ll always need _you_ ,” Tony mumbled against his lips and Steve put both hands low on the Omega’s ass to yank him up, closing the distance.  
  
Both of them groaned and swallowed each other’s sounds in a passionate kiss. The Alpha found his lips already parted and slid his tongue inside, squeezing and kneading the perfectly round curve of Tony’s rear, until the Omega whined and spread his legs further, wriggling closer so they were fit tight together.  
  
“I love you too, sweetheart,” Steve sealed his lips over his throat and sucked lightly on it sending a shiver through the Omega who exposed his neck more, submitting to the Alpha. “Sweet, sweet Omega,” he rumbled, and bit down hard, making Tony _mewl_ hoarse, his body lit up with sparks, and he was getting wet where Steve’s hands were rubbing, spreading his cheeks still above the under-suit’s skintight pants.  
  
“Dads, I’m done! Tell them J- _Uugh_ ”  
  
Both of them turned their heads to the little Omega who was scrunching his nose, looking at them basically disgusted. That was still a good reaction at least: the first time Mary caught them making out, her Alpha instincts made her try to assault Steve as if he was hurting her Omega parent. Then, for a week, she drew her family putting the big Alpha in the very corner of the papers, far away from the two Omegas he had to protect.  
  
Tony huffed a soft laugh, while Steve let his head drop onto Tony’s shoulder, still looking at Peter, and growled quietly to calm him. Their children were the only ones who could interrupt them during those particular moment, without suffer the consequences. Steve made anyone else regrets that choice, even if unintentional like in most cases – and Tony’s rage was no better: never intrude while they were _canoodling_ , if you didn’t want to hear a never-ending scolding, by a very growling and very disgruntled Omega.  
  
He sighed feeling Steve’s hands placing harmlessly on the small of his back. “Do you want a kiss too, cupcake?” Tony opened an arm toward the little Omega, but he looked down to the floor and didn’t get close.  
  
“Wade said we are too old to get kisses,” he muttered, so low the parents almost missed the words. They exchanged a confused look and Tony freed himself from Steve’s embrace, to reach his baby.  
  
“Hey,” Tony breathed, while lowering to Peter’s level. “You know who is very old?” He waited for Peter to shake his head, the added: “Your Pops is, he’s almost _two hundred_ ,” he exaggerated, stretching the words to emphasize them, and Peter chuckled a little. Steve murmured something like: “I’m barely a hundred”, but they ignored him.  
  
“Nevertheless, he gets kisses every day: by me, by you and Mary, sometimes even by aunt Tasha and uncle Bucky. Oh, we aren’t supposed to know the last thing, so keep acting like you don’t when Bucky’s here. Or don’t, if they feel their Alphaness threatened because we know they kiss each other, that’s their problem,” a cough interrupted Tony’s rambling, who smiled and continued.  
  
“Anyway, do you think we should stop kissing him?”  
  
“No!” Peter answered stridently, almost scared by the idea. “I enjoy kissing Pops,” then he glanced at Steve with the most adorable pout, an evidence he obviously inherited the sad and wet puppy look from the big Alpha.  
  
“Then, my pup, nobody can be too old to be kissed. Kisses have no age, just like me,” he concluded with a big smack on Peter’s cheek, making it sound loud on purpose. Peter nodded and run to Steve, he climbed on the sofa and then on the Alpha, and they hugged tightly right after the little Omega gave him a kiss in the same way he received the previous from Tony. A peaceful rumble from the Alpha made Peter relaxing, who responded with little soft purrs. He hasn’t learned to control them well yet, they came out instinctively in those sweet moment, and only with his parents.  
  
“Did Wade say anything else?” Steve asked curious, his tone very calm. Tony knew anyway he was more worried than he was showing. They couldn’t never let their guards down with Logan’s baby.  
  
Peter nodded and curled into his Pops’ big chest, sitting on his laps, just like Tony did more often than not.  
  
“He said when we grow up, he’s gonna be Ned’s Alpha and mine,” his face became bright red, but he let his words out with no embarrassment. He sounded quite proud actually, and Tony recognized when Steve’s Alpha instincts kicked in, by the way he was looking at Peter.  
  
“Fine! It’s bedtime story! Go get ready Petey, we’ll arrive in a moment,” Tony called out before Steve had a chance to say something he’d regret and clapped his hands to get Peter’s attention. The little Omega, still too young to read and to feel certain Alpha behaviors, squealed excited and climbed off Steve, but he suddenly stopped before closing the door, to look at Tony with a serious look.  
  
“Can you tell Snow White, please?”  
  
“Again? Hmm, I think Prince Charming woke up Prince Tony too many times this week. Let them sleep peaceful together, tonight I’ll tell you the legend of Tony of Locksley, a heroic outlaw, also known as Iron Hood,” he made a gesture with a hand to make him get out, with an encouraging smile on his lips.  
  
Tension rose when Peter left the room, the Omega felt it on his skin. After a few seconds of heavy silence, he heard snarls ripping from the Alpha’s throat, his jaw set in a hard line, his instincts were surging and he felt the need to stop him, to reassure his Alpha everything was fine, no one would’ve taken away his children from him. Tony ran to gather his mate close, running his hands soothingly over his body, and murmuring into his ear. He kissed Steve many times, on his earlobe, on both eyelids, on the tip of his nose and finally on his lips, hearing the growl reducing kiss after kiss.  
  
Tony wasn’t scared, he treated his Alpha gently in the way he knew he could bring him back. Steve’s anger was weaker only than the anxiety to frighten his Omega, and luckily for him, he was that Omega.  
  
“Hi,” he said playfully, when he heard nothing but Steve’s regular breath. “I’ve lost you for a moment”  
  
Steve hummed, carefully pulling Tony’s hands away from his face, but keeping them in his own, so they were staring into each other’s eyes. “I’m calling Logan,” he said, ducking in to press a kiss on his forehead.  
  
“I know you are, tomorrow though. Peter’s not going anywhere, and he won’t be able to mate for another five years, at least. And besides, he could choose another Omega or a Beta, or he could never feel the need to love someone, or even to mate-”  
  
“Okay, Tony okay, messaged received. I’m sorry about my reaction, I shouldn’t have…”  
  
“I got you big guy, you’re pretty strong and I can handle you just fi-”  
  
“I know you can, that doesn’t mean I may be snappy and growly around you,” a corner of his mouth quirked up at the end, and Tony was sure he said those words first.  
  
“You could control yourself ‘til the little one left, that was enough. You know you can always let it out with me, right? Don’t beat your gorgeous self up, I’m here for a reason too”  
  
“Thank you,” Steve rumbled quietly and touched their foreheads together.  
  
“And it’s not like I don’t get all hot and bothered when my Alpha put up a show of protectiveness,” he yelped when he got another light slap on his rear.  
  
Right, he has told Steve to hold that thought, didn’t he? First Peter’s and almost certainty Mary’s bedtime story, then sweet, sweet time for him with the big Alpha.  
  
~~~  
  
JARVIS turned down the lights as the two parents exited their children’s bedroom, and when Tony didn’t hear Steve’s steps behind him anymore, he turned around to look up at him. The Alpha was resting his hand on the door handle, a lovely smile on his lips.  
  
Tony felt his heart floating, and the butterflies in his stomach. No matter how many years passed since the first time he met Steve, since he got to knew him and he fell in love with him completely and helplessly: seeing him with an expression like that, outside their puppies’ room, still could make him feel like a teenager struggling with his biggest, memorable, first love. In that moment, he thought he’d went through all the troubles, all the pain, all the misunderstanding and all the risks all over again, because it meant to get to that exact point where they were happy, madly in love, and with a beautiful family. Maybe not perfect, but they weren’t perfect themselves: they fit right together.  
  
Tony approached him putting a hand on his shoulder, got up on his tiptoes and whispered words so sweet and intimate they had to be declared with the sweetest voice, as if they were something sacred and they had to protect carefully them.  
  
“ _We belong to you, beloved_ ”.

**Author's Note:**

> [Send me a Stony prompt on Tumblr!](http://blue-awesome-pumpkin.tumblr.com/post/183195743564/send-me-a-stony-prompt#c-screen) Don't be shy, 'cause I am, already.  
> Also, say hello to me will make me very happy!


End file.
